title: Central obesity in asymptomatic volunteers is associated with increased intrasphincteric acid reflux and lengthening of the cardiac mucosa.
abstract: OBJECTIVE
  In the West, a substantial proportion of subjects with adenocarcinoma of the gastric cardia and gastroesophageal junction have no history of reflux. We studied the gastroesophageal junction in asymptomatic volunteers with normal and large waist circumferences (WCs) to determine if central obesity is associated with abnormalities that might predispose individuals to adenocarcinoma.
  
  
  METHODS
  We performed a study of 24 healthy, Helicobacter pylori-negative volunteers with a small WC and 27 with a large WC. Abdominal fat was quantified by magnetic resonance imaging. Jumbo biopsy specimens were taken across the squamocolumnar junction (SCJ). High-resolution pH-metry (12 sensors) and manometry (36 sensors) were performed in upright and supine subjects before and after a meal; the SCJ was visualized fluoroscopically.
  
  
  RESULTS
  The cardiac mucosa was significantly longer in the large WC group (2.5 vs 1.75 mm; P = .008); its length correlated with intra-abdominal (R = 0.35; P = .045) and total abdominal (R = 0.37; P = .034) fat. The SCJ was closer to the upper border of the lower esophageal sphincter (LES) in subjects with a large WC (2.77 vs 3.54 cm; P = .02). There was no evidence of excessive reflux 5 cm above the LES in either group. Gastric acidity extended more proximally within the LES in the large WC group, compared with the upper border (2.65 vs 4.1 cm; P = .027) and peak LES pressure (0.1 cm proximal vs 2.1 cm distal; P = .007). The large WC group had shortening of the LES, attributable to loss of the distal component (total LES length, 3 vs 4.5 cm; P = .043).
  
  
  CONCLUSIONS
  Central obesity is associated with intrasphincteric extension of gastric acid and cardiac mucosal lengthening. The latter might arise through metaplasia of the most distal esophageal squamous epithelium and this process might predispose individuals to adenocarcinoma.
authors.affiliation: Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
authors.forename: Elaine V
authors.initials: EV
authors.lastname: Robertson
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Derakhshan
authors.forename: Angela A
authors.initials: AA
authors.lastname: Wirz
authors.forename: Yeong Yeh
authors.initials: YY
authors.lastname: Lee
authors.forename: John Paul
authors.initials: JP
authors.lastname: Seenan
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Ballantyne
authors.forename: Scott L
authors.initials: SL
authors.lastname: Hanvey
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Kelman
authors.forename: James J
authors.initials: JJ
authors.lastname: Going
authors.forename: Kenneth E L
authors.initials: KE
authors.lastname: McColl
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002299:Cardia / Q000473:pathology*; D049630:Esophageal Sphincter, Lower / Q000473:pathology; D005260:Female; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000209:etiology*; D006801:Humans; D008297:Male; D008365:Manometry; D008679:Metaplasia; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D009765:Obesity / Q000150:complications* / Q000473:pathology; D055105:Waist Circumference
keywords: BMI; Cancer Risk; Cardia Histology; GEJ; GI; IGP; IQR; Intrasphincteric Reflux; LES; MRI; Overweight; PIP; SCJ; TLESRs; WC; body mass index; gastroesophageal junction; gastrointestinal; interquartile range; intragastric pressure; lower esophageal sphincter; magnetic resonance imaging; pressure inversion point; squamocolumnar junction; transient lower esophageal sphincter relaxations; waist circumference